How people were convinced to drink despite not being thirsty

Groundbreaking new book debunks myths spread by sports drink industry

CHAMPAIGN, IL—According to Beverage Industry Magazine, sales of sports drinks in the United States now exceed a staggering $3 billion annually. Internationally recognized human performance expert Tim Noakes credits much of the rise in the popularity of these drinks to the industry’s modern marketing tactics and the strength of a unique positive product image. Unfortunately, these tactics have also led athletes and fitness enthusiasts to falsely believe they are unable to naturally monitor their hydration levels and drink accordingly.

In the forthcoming Waterlogged: The Serious Problem of Overhydration in Endurance Sports (Human Kinetics, 2012), Noakes debunks beliefs about hydration that have taken hold over the past 30 years. He shows how the past three decades have been not only a time of runaway success for the sports drink industry but also a time in which an epidemic of exercise-associated hyponatremia (EAH), a potentially fatal condition caused by overdrinking during extended exercise, has struck endurance athletes worldwide. “If drinking during exercise was so important,” Noakes says, “then why should a product that contains no unique molecules ever be taken seriously, especially if its core ingredients of glucose, salt, water, and a dash of lemon are present in even the most rudimentary kitchen?”

As Noakes’ research shows, sports drink industry marketing methods have helped sustain the idea that dehydration is a condition with a specific set of symptoms (like confusion, dizziness, nausea, cramping, and fainting) that can be diagnosed and prevented, such as by ingesting more sports drinks during exercise. “Of course, if a patient’s symptoms are not due to a reduction in the total-body water, then those symptoms caused by some other condition will not disappear when the patient is either told to drink more or is treated with intravenous fluids after exercise,” Noakes says. As a result, he believes the treatments are more likely to cause or exacerbate the underlying condition.

Noakes, also a medical doctor and an exercise physiologist, stresses that the only symptom of dehydration is thirst; it is not a medical condition or disease that produces a variety of unique symptoms. So, if an otherwise healthy athlete seeking medical care is not thirsty, it is unlikely that dehydration is the cause of any illness or symptoms that may be present at the same time. “Not surprisingly,” Noakes points out, “thirst is an uncommon complaint in athletes treated during and after endurance events in which fluid is freely available.” As well as being an uncommon complaint, thirst is not even listed as a symptom of dehydration by those who have promoted it as a disease.

Noakes believes that the widespread disinformation about the need for sports drinks to treat dehydration helps explain why doctors often treat patients incorrectly, thinking those patients are dehydrated when, in reality, they are overhydrated. “It is disturbing that incorrect advice to the public and the public’s own susceptibility to promotional efforts resulted in a novel medical condition that affected thousands of soldiers, hikers, runners, cyclists, and triathletes, causing some to die,” Noakes comments. “Sadly, this phenomenon and the deaths that apparently resulted from it were preventable.”

Noakes believes that as bad as water restrictions and required ingestion of salt tablets were during the 1960s, so too is the current, and nearly universal, notion of drinking despite lack of thirst. He sees today’s athletes, parents, coaches, and even many professionals in medicine, fitness, and sport science pushing the intake of fluid far beyond the bounds of what solid research suggests. “Indeed,” Noakes contends, “tens of millions of athletes and fitness enthusiasts are waterlogged in that the hydration practices to which they religiously adhere adversely affect their health and performance.”

Waterlogged: The Serious Problem of Overhydration in Endurance Sports outlines practices that endurance athletes should follow, variables they should consider, and guidelines they should use in maintaining proper fluid balance in sport training and performance.

For more information, see Waterlogged.

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About the Author

Known throughout the academic community for the high-caliber nature of his scientific insights and work, Dr. Timothy Noakes is Discovery Health professor of exercise and sport science at the University of Cape Town in South Africa. He is also director of the Medical Research Council/University of Cape Town Research Unit for Exercise Science and Sports Medicine at the Sports Science Institute of South Africa in Newlands. Noakes was awarded a doctorate in science (DSc) in 2002, the highest degree awarded by the University of Cape Town. Publishing the first scientific article on exercise-associated hyponatremia (EAH) is considered among his greatest achievements.

Noakes is a veteran of more than 70 marathons and ultramarathons, and his book Lore of Running (Human Kinetics, 2003) is considered a classic by serious distance runners. In addition, Noakes is an editorial board member for many international sport science journals and a former president of the South African Sports Medicine Association. In 1996, he presented the prestigious J.B. Wolffe Memorial Lecture at the American College of Sports Medicine’s annual meeting. In 1999 he was elected as one of 22 founding members of the International Olympic Committee’s Olympic Science Academy. The National Research Foundation of South Africa considers Noakes an A-rated scientist, and in 2008 he received the Order of Mapungubwe (Silver) from the president of South Africa.

Noakes and his wife, Marilyn Anne, reside in Cape Town.

Contents

Chapter 1. Perspectives on Human Physiology and Hydration

Chapter 2. Thirst as a Signal for Fluid Intake

Chapter 3. Water’s Role in Thermoregulation

Chapter 4. Salt Balance in the Body

Chapter 5. Emergence of the Sports Drink Industry

Chapter 6. The Shaky Science of Hydration

Chapter 7. Early Drinking Guidelines

Chapter 8. Discovery of Exercise-Associated Hyponatremia (EAH)

Chapter 9. The Biology of EAH

Chapter 10. EAH and EAHE on a Global Scale

Chapter 11. Guidelines for Fluid Intake and Diagnosis of EAH

Sample questions for Tim Noakes

What role has the marketing of sports drinks played in the rise of exercise-associated hyponatremia (EAH) over the past three decades?

What role has the encouragement of frequent drinking during marathons and other endurance sports had on world-record performances, and how do performances compare to the time before drinking was pushed so much?

How do the symptoms of EAH differ from those of dehydration, and how has confusion between the two affected the way in which they are treated?

What to you is the most dangerous aspect of the way in which sports drinks are marketed to athletes, and how has the zero % dehydration rule run counter to evidence that humans have the ability to sweat profusely and regulate body temperatures during exercise?

How did the introduction of frequent drinking stations at marathon and ultramarathon races in 1981 impact the amount of medical care needed to treat runners at those races?

What is your stance on the debate of whether or not it is “safe” to lose some body weight during exercise, and do you feel that the body will decide itself the safe level of dehydration that it will allow during exercise?

How did humans develop as long-distance runners especially well adapted to run in extreme dry heat in the middle of the day while drinking infrequently and conserving body sodium stores?

What are your thoughts on the way the sports drink industry has convinced athletes that they lack biological controls to ensure that they ingest enough salt and are therefore at risk of developing a syndrome of salt deficiency?

What is the relationship between dehydration and heatstroke, and why don’t you believe that the only way to prevent heatstroke during exercise is to drink plenty of fluids?

How have the way college football players sweat during practice provided further evidence against the dehydration myth?

Background Facts

The introduction and encouragement of frequent drinking after 1976 were not associated with any sudden increase in world-record performances in the marathon. Rather, an opposite trend is apparent. The same trend exists also at the shorter-distance races, during which athletes do not usually drink.

Participation in individual marathons increased from only a few hundred entrants each year to over 30,000 in big-city marathons, with a total of 400,000 runners competing in marathons in the United States in 2008.

The symptoms of exercise-associated hyponatremia are not the same as those of dehydration. In fact, they are distinctly different. For a start, the dehydration that develops during exercise has only one symptom: thirst. Confusion arising from this distortion has resulted in the inappropriate treatment of athletes suffering from hyponatremia.

One advantage of being small is that at any running speed, smaller mammals generate less heat and so need to lose less water by either panting or sweating to maintain a safe body temperature. This helps to explain why elite distance runners are inevitably small—about 110 lb for both men and women—and how being lighter by even a few pounds can produce a large competitive advantage when running in the heat.

The level of dehydration at which humans become physically disabled and at risk of dying is central to the debate of how much athletes should drink during exercise. Before the development of the world’s first sports drink, this topic drew little discussion. Rather, it was assumed that humans could safely exercise for perhaps 8 to 10 hours in the heat while requiring little fluid replacement. But with the development of the world’s first sports drink, the concept arose that athletes should drink as much as tolerable to ensure that they do not lose any weight during exercise.

The commercial success of the world’s first sports drink in the 1990s was driven at least in part by the development of the zero % dehydration rule, which holds that any level of voluntary dehydration that develops during exercise is profoundly undesirable, indeed dangerous, and could be fatal. Instead, to prevent this potentially catastrophic “disease,” exercising humans are taught to replace their sweat losses as they develop. But this advice ignores all the evidence that humans have an unmatched capacity to sweat profusely specifically so that they can better regulate their body temperatures during exercise.

Three original Gatorade-funded studies performed in the laboratories of Drs. David Costill, Carl Gisolfi, and Edward Coyle did indeed show that the ingestion of fluid during exercise lowers the body temperature during exercise. But the value of this effect was not shown because none of the studies included a measure of performance. Rather, it was originally assumed that fluid ingestion would improve exercise performance if it also lowered the body temperature. In this way did the body temperature during exercise become a surrogate measure of both performance and the risk that heat illness would develop.

The total absence of evidence that not drinking during exercise was dangerous would be used as the basis for drinking guidelines that, beginning in the 1990s, would encourage athletes to drink without restraint before, during, and after exercise.

Only after the introduction of frequent (every 1.6 km) drinking stations in 1981 did it become increasingly necessary to provide medical care at the finish of marathon and ultramarathon races to treat the growing proportion of collapsed runners seeking medical care for “dehydration” and “heat illness.” The most likely reason that treatment was necessary was the changing nature of the runners entering marathon and ultramarathon races. Before the running boom that began after 1976, only those who were reasonably trained would ever consider entering those races. But the culture became very different thereafter. The new generation of runners was not told to train more to ensure that they did not suffer harm during those races. Instead they were advised to drink more.

Dehydration is a physiological term indicating a reduction in the total-body water content. Once the reduction in body water causes the solute concentration, especially the sodium concentration (actually the osmolality), of the blood to rise, the brain detects the change and develops the symptom of thirst. This is a normal biological response that has evolved in all creatures to ensure that they maintain a constant body water content at least once each day, usually after the evening meal.

If thirst cannot be quenched because fluid is unavailable, as occurs in those stranded in the desert, the body activates a series of emergency adaptations that prolong life for a period but ultimately cause death when all the major bodily organs fail, leading probably to cardiovascular collapse. The remarkable achievement of the sports drink industry was that it convinced recent generations that these control mechanisms do not exist. Instead all athletes must drink to insure that they do not lose any body weight during exercise. But there are no known receptors that regulate thirst by monitoring the extent of the body weight lost or gained. In addition, this myth also convinced exercisers that they could become dangerously dehydrated not just when lost in the desert for more than 48 hours but when running for a few minutes in, for example, a big-city marathon, during which they have unrestricted access to as much fluid as they might wish.

Facts taken from Waterlogged.

Endorsements

“Finally, an unbiased look at fluid replacement: the real science behind thirst, fluid balance, and thermoregulation during exercise! Waterlogged is a must-read for athletes, coaches, parents, and sports medicine professionals.”